Somatic mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene in lung cancers have generated enormous interest, providing an approach to predict for sensitivity to TK inhibitors (TKIs). While mutational status is of great importance in determining response to TKIs, it is not the sole factor, and evidence is accumulating that EGFR gene amplification, other members of the EGFR family (HER2, HER3) and genes downstream of EGFR signaling (KRAS, BRAF), may be involved in cancer pathogenesis and the response of TKIs.
WO 2006/084058 discloses a method for the treatment of gefitinib and/or erlotinib resistant cancer comprising administered a pharmaceutical composition comprising an irreversible epidermal growth factor receptor (EGFR) inhibitor to a person in need of such treatment, specifying the irreversible EGFR inhibitors EKB-569, HKI-272 and HKI-357.
Epithelial cell cancers, for example, prostate cancer, breast cancer, colon cancer, lung cancer, pancreatic cancer, ovarian cancer, cancer of the spleen, testicular cancer, cancer of the thymus, etc., are diseases characterized by abnormal, accelerated growth of epithelial cells. This accelerated growth initially causes a tumor to form. Eventually, metastasis to different organ sites can also occur. Although progress has been made in the diagnosis and treatment of various cancers, these diseases still result in significant mortality.
Lung cancer remains the leading cause of cancer death in industrialized countries. Cancers that begin in the lungs are divided into two major types, non-small cell lung cancer and small cell lung cancer, depending on how the cells appear under a microscope. Non-small cell lung cancer (squamous cell carcinoma, adenocarcinoma, and large cell carcinoma) generally spreads to other organs more slowly than does small cell lung cancer. About 75 percent of lung cancer cases are categorized as non-small cell lung cancer (e.g., adenocarcinomas), and the other 25 percent are small cell lung cancer. Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths in the United States, Japan and Western Europe. For patients with advanced disease, chemotherapy provides a modest benefit in survival, but at the cost of significant toxicity, underscoring the need for therapeutic agents that are specifically targeted to the critical genetic lesions that direct tumor growth (Schiller J H et al., N Engl J Med, 346: 92-98, 2002).
Two of the more advanced compounds in clinical development include Gefitinib (compound ZD 1839 developed by AstraZeneca UK Ltd.; available under the tradename IRESSA; hereinafter “IRESSA”) and Erlotinib (compound OSI-774 developed by Genentech, Inc. and OSI Pharmaceuticals, Inc.; available under the tradename TARCEVA; hereinafter “TARCEVA”); both have generated encouraging clinical results. Conventional cancer treatment with both IRESSA and TARCEVA involves the daily, oral administration of no more than 500 mg of the respective compounds. In May, 2003, IRESSA became the first of these products to reach the United States market, when it was approved for the treatment of advanced non-small cell lung cancer patients. IRESSA is an orally active quinazoline that functions by directly inhibiting tyrosine kinase phosphorylation on the EGFR molecule. It competes for the adenosine triphosphate (ATP) binding site, leading to suppression of the HER-kinase axis. The exact mechanism of the IRESSA response is not completely understood, however, studies suggest that the presence of EGFR is a necessary prerequisite for its action.
A significant limitation in using these compounds is that recipients thereof may develop a resistance to their therapeutic effects after they initially respond to therapy, or they may not respond to EGFR-tyrosine kinase inhibitots (TKIs) to any measurable degree at all. The response rate to EGFR-TKIs varies between different ethnic groups. At the low end of EGFR-TKI responders, in some populations, only 10-15 percent of advanced non-small cell lung cancer patients respond to EGFR kinase inhibitors. Thus, a better understanding of the molecular mechanisms underlying sensitivity to IRESSA and TARCEVA would be extremely beneficial in targeting therapy to those individuals whom are most likely to benefit from such therapy.
There is a significant need in the art for a satisfactory treatment of cancer, and specifically epithelial cell cancers such as lung, ovarian, breast, brain, colon and prostate cancers, which incorporates the benefits of TKI therapy and overcoming the non-responsiveness exhibited by patients. Such a treatment could have a dramatic impact on the health of individuals, and especially older individuals, among whom cancer is especially common.
BIBW2992 (1) is known as the compound 4-[(3-chloro-4-fluorophenyl)amino]-6-{[4-(N,N-dimethylamino)-1-oxo-2-buten-1-yl]amino}-7-((S)-tetrahydrofuran-3-yloxy)-quinazoline,

BIBW 2992 (1) is a potent and selective dual inhibitor of erbb1 receptor (EGFR) and erbB2 (Her2/neu) receptor tyrosine kinases. Furthermore, BIBW 2992 (1) was designed to covalently bind to EGFR and HER2 thereby irreversibly inactivating the receptor molecule it has bound to. This compound, salts thereof such as the dimaleate salt, their preparation as well as pharmaceutical formulations comprising BIBW2992 (1) or a salt thereof are disclosed in WO 02/50043 and WO 2005/037824. These documents are incorporated by reference regarding these aspects.